I am looking for a method to find the 3D intersection of two polylines with Z-coordinates. I checked the functions ITopologicalOperator.Intersect and ITopologicalOperator6.IntersectEx. The difference is that IntersectEx has an additional boolean parameter bNonPlanar. What is this parameter for? Is it a switch to get the result in 3D? Thank you!

I understand the nonPlanar parameters now. It has nothing to do with Z-coordinates. It is used to control whether the returned geometry can intersect itself. Refer to the definition of Planar Graph http://en.wikipedia.org/wiki/Planar_graph

Seems I need to do vertex by vertex manipulation to find the 3D intersection...

I understand the nonPlanar parameters now. It has nothing to do with Z-coordinates. It is used to control whether the returned geometry can intersect itself. Refer to the definition of Planar Graph http://en.wikipedia.org/wiki/Planar_graph

Seems I need to do vertex by vertex manipulation to find the 3D intersection...